Strain-insulator for electric lines.



APPLICATION FILED JAN 10.1908

Patented Oct. .26, 1909v M E S S E N n W AT'TORNEY antral) s rars Ion.

nnw'ann ERNEST nosn, or swrssvam, rnNNsYLvaNm, assIeNon, BY MESNE asSIGNMENTS, T0 WESTINGHOUSE nnncrmc & MANUFACTURING COMPANY, or EASTrrrrsnuae, PENNSYLVANIA, A conronarroN or PENNSYLVANIA.

STRAIN -I1\T SULA'I'OR FCE ELECTRIC LINES.

937,867 Specification of Letters Patent. Patented Oct. 26 1909.

Application filedJanuary 10, 1908. Serial 130. 410,248.

To (1, 10710711 "it may concern:

lie it known that l, llnw nn ERNEST Rose, a citizen of the llnitcdStates, and a resident of Swissvale. in the county of Allegheny andState of Pennsylvania, have invented a new and useful In'iprovement inStrainlusulators for Electric Lines, of which the following is aspecification. I

My invention relates to strain insulators for electric lines and it hasfor its object to provide a ('(uupact and durable device of thischaracter that shall be capable of Withstanding strains incident to' theuse of high.

voltages and that shall also embody an improved casing of insulatingmaterial which is exempt from the strains to which the other parts aresubjected.

High-voltage strain insulators, as heretofore constructed, havesometimes comprised metal tubes having tapered ends into whichinsulating tubes and tapered plugs were fitted, the metal tubes beingsurrounded by coatings or jackets of molded insulating material whichextended over the ends of the insulatingtubes.

According to my present invention, I provide an outer casing which isbuilt up of sections and which is so separated from the inner coating orjacket, above mentioned that it is entirely freed from the strains towhich the remainder of the insulator is subjected. The outer casing maybe replaced by another, when desired, and it serves to elfectuallyprotect the insulator proper from the weather.

The single figure of the accompanying drawing is a partially sectionalelevation of a strain insulator constructed in accordance with n'invention. v v r Rel'erring to the drawing, the insulator hereillustrated comprises a metal tube 1 having tapered ends, tapered tubes2 and 3- of insulating material seated in the ends of the metal tube 1,tapered plugs 4 and 5 seated in the insulating tubes and provided withend projections 6 and 7 which extend for a material distance beyond theextremities oi. the insulating tubes, and strain loops 8 and 9 which arescrewed upon the extremities of the projections (i and 7. The insulatingtapered tubes 2 and 3 project materially beyond the ends of the metaltube 1 in order to increase the croepage distance between the plugs 1and 5 and the metal tube. The

interior of the insulator, between the plugs 4 and 5 may preferably befilled with asphalt gum or other insulating material which may be pouredin when hot and allowed to set by cooling to ordinary temperatures. Inorder that a still better protection may be afforded for the entiredevice, I provide a casing 11 comprising two tapered sections 12 and'13of porcelain or and 13 are provided with annular grooves The 18 overwhich the caps 14 and 15 extend, the

caps being secured in place by cement which fills the annular -gzrooves18 and the spaces between the caps and the segments.

1 The caps 14 and 15 are similaflto each other and comprise flanges 19,preferably constructed of cast iron, ,and diaphragms 20 that are fittedover the shanks (5 and 7 and the outer edges of which are cast into orare otherwise secured to the flanges. The diapl 'agms 20 are providedwith annular corrugations between the shanks and the flanges and aresealed to the shanks by set-nuts 21 and 22 which are screwed upon theshanks at the respective sides of the diaphragm.

Although tight joints are formed at the ends of casing 11 the strainswhich are imposed upon the insulator proper are not imparted to thecasin since the annular corrugations in the diaphragms permit of aslight relative movement between the strain parts and the casino. 7Asbestos washers 23 may preferably beinterposed between the casingsegments and the caps and also between the two i agments', and the spacewithin the casihgilnay be filled with an insulatin gum or similarsubstance 10 which is su ficiently yielding to permit,therelativo'rnovement above indi-' able that modifications in theircontours may s siem clu.

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